I wonder among all your surviving workstations, what is your oldest? By surviving, I mean the machine being able to handle some day to day work: run your development tools, build your projects in reasonable time, and stream YouTube with at least 1080p resolution (don't count this anymore.) I remember a few members complaining about slow computers, let's just compare them and maybe figure out a way to get it smooth again.
My oldest system is a recently restored, maxed out Dell Latitude D620 laptop. Specs:
* CPU: Intel Core 2 Duo T7600, 2.33GHz 2C/2T (maxed out)
* RAM: DDR2-667 3GB (maxed out)
* Chipset: Intel 945PM + ICH7M
* Graphics: nVidia Quadro NVS 110M, 64MB VRAM, force installed GeForce Go 7300 drivers (same G72M chip)
* Storage: Kingston SSD 240GB (This makes all the difference)
* OS: Windows 10 Pro amd64 (yes it works perfectly, 64 bit version too.)
As long as Windows Defender is not scanning the downloads, this machine is actually fairly snappy. Eclipse and GCC have been smooth so far, although it is really not my main workstation. I haven't tested KiCad yet, but other than the 3D view I don't see anything potentially lagging.
I had this laptop for more than 10 years already - was it bought back in 2004 or 2005? During the years things have fell apart, but thanks to the used parts market I could fix it and upgrade it to the max without paying too much money. This is my only Windows machine now (since Ubuntu does not have the appropriate graphics driver for the old GPU any more.) My specific laptop have been maxed out on almost all its aspects - maximum RAM, top CPU the chipset would accept, 802.11ac wireless, HSDPA (it does have appropriate antennae and SIM card slot) and replaced the dead optical drive with a secondary hard disk drive.